Normalize context creation for option resolution (#7847)

* Normalize context creation for option resolution
* Pass mode to _computeAngle

src/controllers/controller.bubble.js

@@ -109,18 +109,11 @@ export default class BubbleController extends DatasetController {
 	resolveDataElementOptions(index, mode) {
 		const me = this;
 		const chart = me.chart;
-		const dataset = me.getDataset();
 		const parsed = me.getParsed(index);
 		let values = super.resolveDataElementOptions(index, mode);
 
 		// Scriptable options
-		const context = {
-			chart,
-			dataPoint: parsed,
-			dataIndex: index,
-			dataset,
-			datasetIndex: me.index
-		};
+		const context = me.getContext(index, mode === 'active');
 
 		// In case values were cached (and thus frozen), we need to clone the values
 		if (values.$shared) {

src/controllers/controller.polarArea.js

@@ -59,12 +59,12 @@ export default class PolarAreaController extends DatasetController {
 		me._cachedMeta.count = me.countVisibleElements();
 
 		for (i = 0; i < start; ++i) {
-			angle += me._computeAngle(i);
+			angle += me._computeAngle(i, mode);
 		}
 		for (i = start; i < start + count; i++) {
 			const arc = arcs[i];
 			let startAngle = angle;
-			let endAngle = angle + me._computeAngle(i);
+			let endAngle = angle + me._computeAngle(i, mode);
 			let outerRadius = this.chart.getDataVisibility(i) ? scale.getDistanceFromCenterForValue(dataset.data[i]) : 0;
 			angle = endAngle;
 
@@ -109,7 +109,7 @@ export default class PolarAreaController extends DatasetController {
 	/**
 	 * @private
 	 */
-	_computeAngle(index) {
+	_computeAngle(index, mode) {
 		const me = this;
 		const meta = me._cachedMeta;
 		const count = meta.count;
@@ -120,13 +120,7 @@ export default class PolarAreaController extends DatasetController {
 		}
 
 		// Scriptable options
-		const context = {
-			chart: me.chart,
-			dataPoint: this.getParsed(index),
-			dataIndex: index,
-			dataset,
-			datasetIndex: me.index
-		};
+		const context = me.getContext(index, mode === 'active');
 
 		return resolve([
 			me.chart.options.elements.arc.angle,

src/core/core.datasetController.js

@@ -693,9 +693,9 @@ export default class DatasetController {
 	}
 
 	/**
-	 * @private
+	 * @protected
 	 */
-	_getContext(index, active) {
+	getContext(index, active) {
 		return {
 			chart: this.chart,
 			dataPoint: this.getParsed(index),
@@ -764,7 +764,7 @@ export default class DatasetController {
 		const datasetOpts = me._config;
 		const options = me.chart.options.elements[type] || {};
 		const values = {};
-		const context = me._getContext(index, active);
+		const context = me.getContext(index, active);
 		const keys = optionKeys(optionNames);
 
 		for (let i = 0, ilen = keys.length; i < ilen; ++i) {
@@ -798,7 +798,7 @@ export default class DatasetController {
 		}
 
 		const info = {cacheable: true};
-		const context = me._getContext(index, active);
+		const context = me.getContext(index, active);
 		const chartAnim = resolve([chart.options.animation], context, index, info);
 		const datasetAnim = resolve([me._config.animation], context, index, info);
 		let config = chartAnim && mergeIf({}, [datasetAnim, chartAnim]);

src/core/core.scale.js

@@ -1013,6 +1013,19 @@ export default class Scale extends Element {
 			0;
 	}
 
+	/**
+	 * @protected
+	 */
+	getContext(index) {
+		const ticks = this.ticks || [];
+		return {
+			chart: this.chart,
+			scale: this,
+			tick: ticks[index],
+			index
+		};
+	}
+
 	/**
 	 * Returns a subset of ticks to be plotted to avoid overlapping labels.
 	 * @param {Tick[]} ticks
@@ -1105,12 +1118,7 @@ export default class Scale extends Element {
 		const tl = getTickMarkLength(gridLines);
 		const items = [];
 
-		let context = {
-			chart,
-			scale: me,
-			tick: ticks[0],
-			index: 0,
-		};
+		let context = this.getContext(0);
 		const axisWidth = gridLines.drawBorder ? resolve([gridLines.borderWidth, gridLines.lineWidth, 0], context, 0) : 0;
 		const axisHalfWidth = axisWidth / 2;
 		const alignBorderValue = function(pixel) {
@@ -1172,15 +1180,7 @@ export default class Scale extends Element {
 		}
 
 		for (i = 0; i < ticksLength; ++i) {
-			/** @type {Tick|object} */
-			const tick = ticks[i] || {};
-
-			context = {
-				chart,
-				scale: me,
-				tick,
-				index: i,
-			};
+			context = this.getContext(i);
 
 			const lineWidth = resolve([gridLines.lineWidth], context, i);
 			const lineColor = resolve([gridLines.color], context, i);
@@ -1318,12 +1318,7 @@ export default class Scale extends Element {
 		const gridLines = me.options.gridLines;
 		const ctx = me.ctx;
 		const chart = me.chart;
-		let context = {
-			chart,
-			scale: me,
-			tick: me.ticks[0],
-			index: 0,
-		};
+		let context = me.getContext(0);
 		const axisWidth = gridLines.drawBorder ? resolve([gridLines.borderWidth, gridLines.lineWidth, 0], context, 0) : 0;
 		const items = me._gridLineItems || (me._gridLineItems = me._computeGridLineItems(chartArea));
 		let i, ilen;
@@ -1364,12 +1359,7 @@ export default class Scale extends Element {
 		if (axisWidth) {
 			// Draw the line at the edge of the axis
 			const firstLineWidth = axisWidth;
-			context = {
-				chart,
-				scale: me,
-				tick: me.ticks[me._ticksLength - 1],
-				index: me._ticksLength - 1,
-			};
+			context = me.getContext(me._ticksLength - 1);
 			const lastLineWidth = resolve([gridLines.lineWidth, 1], context, me._ticksLength - 1);
 			const borderValue = me._borderValue;
 			let x1, x2, y1, y2;
@@ -1597,13 +1587,7 @@ export default class Scale extends Element {
 		const me = this;
 		const chart = me.chart;
 		const options = me.options.ticks;
-		const ticks = me.ticks || [];
-		const context = {
-			chart,
-			scale: me,
-			tick: ticks[index],
-			index
-		};
+		const context = me.getContext(index);
 		return toFont(resolve([options.font], context), chart.options.font);
 	}
 }

src/scales/scale.radialLinear.js

@@ -96,12 +96,7 @@ function fitWithPointLabels(scale) {
 	for (i = 0; i < valueCount; i++) {
 		pointPosition = scale.getPointPosition(i, scale.drawingArea + 5);
 
-		const context = {
-			chart: scale.chart,
-			scale,
-			index: i,
-			label: scale.pointLabels[i]
-		};
+		const context = scale.getContext(i);
 		const plFont = toFont(resolve([scale.options.pointLabels.font], context, i), scale.chart.options.font);
 		scale.ctx.font = plFont.string;
 		textSize = measureLabelSize(scale.ctx, plFont.lineHeight, scale.pointLabels[i]);
@@ -185,12 +180,7 @@ function drawPointLabels(scale) {
 		const extra = (i === 0 ? tickBackdropHeight / 2 : 0);
 		const pointLabelPosition = scale.getPointPosition(i, outerDistance + extra + 5);
 
-		const context = {
-			chart: scale.chart,
-			scale,
-			index: i,
-			label: scale.pointLabels[i],
-		};
+		const context = scale.getContext(i);
 		const plFont = toFont(resolve([pointLabelOpts.font], context, i), scale.chart.options.font);
 		ctx.font = plFont.string;
 		ctx.fillStyle = plFont.color;
@@ -208,12 +198,7 @@ function drawRadiusLine(scale, gridLineOpts, radius, index) {
 	const circular = gridLineOpts.circular;
 	const valueCount = scale.chart.data.labels.length;
 
-	const context = {
-		chart: scale.chart,
-		scale,
-		index,
-		tick: scale.ticks[index],
-	};
+	const context = scale.getContext(index);
 	const lineColor = resolve([gridLineOpts.color], context, index - 1);
 	const lineWidth = resolve([gridLineOpts.lineWidth], context, index - 1);
 	let pointPosition;
@@ -440,12 +425,7 @@ export default class RadialLinearScale extends LinearScaleBase {
 			ctx.save();
 
 			for (i = me.chart.data.labels.length - 1; i >= 0; i--) {
-				const context = {
-					chart: me.chart,
-					scale: me,
-					index: i,
-					label: me.pointLabels[i],
-				};
+				const context = me.getContext(i);
 				const lineWidth = resolve([angleLineOpts.lineWidth, gridLineOpts.lineWidth], context, i);
 				const color = resolve([angleLineOpts.color, gridLineOpts.color], context, i);
 
@@ -496,17 +476,11 @@ export default class RadialLinearScale extends LinearScaleBase {
 		ctx.textBaseline = 'middle';
 
 		me.ticks.forEach((tick, index) => {
-			const context = {
-				chart: me.chart,
-				scale: me,
-				index,
-				tick,
-			};
-
 			if (index === 0 && !opts.reverse) {
 				return;
 			}
 
+			const context = me.getContext(index);
 			const tickFont = me._resolveTickFontOptions(index);
 			ctx.font = tickFont.string;
 			offset = me.getDistanceFromCenterForValue(me.ticks[index].value);